I never did the research my good friend, but from what I was told by tech is that since the fuel lines use pressure to get the fuel from the tank to the cylinders is that when running on fumes you risk a chance of hurting the injectors by pumping air into it or some shit along those lines lololol

I think some say to keep ur tank always above 1/4th just to be on the safe side again this is just stuff I hear people say